Portable Stroke Detection Devices for Patients with Stroke Symptoms: A Review of Diagnostic Accuracy and Cost-Effectiveness

Abstract

Stroke is a highly prevalent and potentially life-threatening medical emergency that requires prompt recognition and treatment in order to minimize morbidity and mortality. In Canada, there are an estimated 62,000 stroke events that occur each year. Moreover, stroke is the third leading cause of death in Canada, comprising nearly 14,000 deaths annually. Mortality rates have improved over time, possibly due to the establishment of integrated regional stroke systems, stroke unit care to prevent and manage complications, and decreases in stroke severity as a result of improved risk factor management. Despite this, over 740,000 Canadian adults over the age of 20 years are living with the effects of stroke (e.g., neurologic deficits, such as hemiparesis, aphasia, and sensory and cognitive deficits).A stroke is the acute neurologic injury that occurs as a consequence of sudden loss of focal brain function due to cell death from poor or interrupted blood flow within the brain., There are two broad categories of stroke that have vastly different treatment approaches. Ischemic strokes are the most common type (80% of all stroke events) and are generally caused by a sudden blood vessel blockage. Hemorrhagic strokes are caused by a rupture of an artery in the brain. It is vital to differentiate between these two different types, as the treatment approaches are entirely different. Great efforts are made to minimize time delays in treatment, as delays are associated with worse outcomes, including death.If an individual experiences a stroke in the community, the Emergency Medical Service (EMS) is usually called to the scene. Currently, EMS workers rely on patient history, physical examination (e.g., a tool that includes components of Face, Arm, Speech, and Time [FAST], such as National Institutes of Health Stroke Scale [NIHSS] or Los Angeles Motor Scale [LAMS]), and some diagnostic testing (e.g., blood glucose) to reach a pre-hospital diagnosis of stroke and to determine stroke severity. A pre-hospital assessment helps to determine what resources are required to appropriately treat the patient and thereby informs next steps, including whether to transport the patient to a stroke centre or the closest medical hospital. A more objective way to diagnose a patient at this stage may be using a portable stroke detection device. A portable stroke detection device is a health technology aimed to detect strokes in the pre-hospital environment by observing changes in blood flow to the brain using alternative ambulatory stroke detection methods (e.g., ultrasound, cranial electrodes., The use of portable stroke detection devices may increase the likelihood of pre-hospital diagnoses of stroke, which in turn could facilitate earlier initiation of stroke care (e.g., routing the patient to a stroke centre, earlier neurovascular imaging in-hospital, and definitive stroke therapies with thrombolysis/endovascular treatment if warranted)., However, there is a lack of clarity on the diagnostic accuracy and cost-effectiveness of portable stroke detection devices for patients with stroke symptoms.A previous CADTH report (summary with critical appraisal) examined the diagnostic accuracy and cost-effectiveness of portable stroke detection devices for adults experiencing symptoms of stroke, including: combination of transcranial Doppler ultrasound, robotic headset blood flow monitor, and machine learning; bioimpedance spectroscopy visor (which uses volumetric impedance phase-shift spectroscopy); and microwave tomography system). The current report extends upon this previous report by evaluating the evidence regarding the diagnostic accuracy and cost-effectiveness of alternative ambulatory stroke detection methods for patients with symptoms of stroke (no age restriction) not covered in the previous report.